Fabrication of a film on a substrate generally requires a stream of molecules, atoms, or ions directed toward the substrate. This stream condenses to form a solid state film on the appropriate substrate surface, generally such deposition methods are termed as Physical Vapor Deposition (PVD). Examples include Pulsed Laser Deposition (PLD) and Pulsed Electron Deposition (PED). The extremely high energy density pulse of from the laser or electron beam can ablate the target (turn some amount of solid target into plasma). This plasma expands outward towards the target in the form of a plasma plume with a composition comprising the target compounds.
To enable PED an electron beam source is required providing an electron beam energy density of ≥108 W/cm2 at the target surface. Known apparatuses and methods to produce such electron beams (U.S. Pat. No. 7,557,511 or WO2011IT00301) are based on channel-spark discharge (CSD) introduced in U.S. Pat. No. 5,576,593 by C. Schultheiss. The CSD apparatus comprises a hollow cathode plasma source, with an activation group to trigger the plasma generation, and a dielectric tubular element. The tubular element guides the flux of electrons extracted from the hollow cathode plasma towards the target which serves as an anode. Under optimal conditions, which are strongly dependent on the pressure in a process chamber, as described in U.S. Pat. No. 7,557,511, it is possible to generate well-collimated beam directed by the tube, which emerges from its exit, and is able to propagate beyond the tube due to the beam-induced space charge neutralization.
The PED technique has been used to manufacture different types of films comprising metals, semiconductors, and dielectric materials coatings having superior quality. In spite of successful deposition experiments in a number of worldwide laboratories, there is as yet no successful industrial application of the pulsed electron beam for deposition of thin films. The main reason that the electron beam source based on CSD has failed for industrial applications is because of the short life-time (generally <108 shots) of the dielectric tubular element, low reproducibility of the pulses from-shot-to-shot, and scalability problems for wide area deposition.